OT: Barstward patronising car mechanics!

rjsterry

davis wrote:

NGale wrote:

In the case of belt drives, friction is your friend. You actually want a higher coefficient of friction in order to prevent slippage. So yes friction would be less on the teflon pulley, but you would want to use the granite pulley in order to the belt to 'stick'

Yup, so... back to my original question (sort of): Are the two pulleys made of the same stuff?

I'm no engineer, but I can't imagine there are that many different steels they'd use.

veronese68

Plastic.

rjsterry

Veronese68 wrote:

Plastic.

[googles] So they are. Would have thought plastic would have not been up to the job. I did say I was no engineer :oops:

nicklouse

Which engin was it?

I may beable to give the exact material spec.

veronese68

rjsterry wrote:

Veronese68 wrote:

Plastic.

[googles] So they are. Would have thought plastic would have not been up to the job. I did say I was no engineer :oops:

Lots of stuff is plastic now. Materials technology has moved on a huge amount. But working with parts for old cars as I do it's amazing how many people when offered a part in a better material say no and go for the original material even though the part will never be seen.

rjsterry

Veronese68 wrote:

rjsterry wrote:

Veronese68 wrote:

Plastic.

[googles] So they are. Would have thought plastic would have not been up to the job. I did say I was no engineer :oops:

Lots of stuff is plastic now. Materials technology has moved on a huge amount. But working with parts for old cars as I do it's amazing how many people when offered a part in a better material say no and go for the original material even though the part will never be seen.

My materials knowledge is based on the construction industry, and as has been demonstrated, of limited application to the motor industry.

veronese68

rjsterry wrote:

Veronese68 wrote:

rjsterry wrote:

Veronese68 wrote:

Plastic.

[googles] So they are. Would have thought plastic would have not been up to the job. I did say I was no engineer :oops:

Lots of stuff is plastic now. Materials technology has moved on a huge amount. But working with parts for old cars as I do it's amazing how many people when offered a part in a better material say no and go for the original material even though the part will never be seen.

My materials knowledge is based on the construction industry, and as has been demonstrated, of limited application to the motor industry.

Aaah now materials technology in the building industry does contain black magic. Push fit plumbing and plastic pipes. I know it works, I know it's been used on the continent for longer than we have. But surely theres magic in there.

The Rookie

NGale wrote:

Most cars these days have Vee belts, hence why the old stocking trick won't work as they are essentially a flat belt.

All cars have V-belts (well 99.9%) modern cars have poly-Vee where a stocking won't work, but they work fine on older (single) Vee belt pulleys.....more study needed?

Simon

rjsterry

Veronese68 wrote:

rjsterry wrote:

Veronese68 wrote:

rjsterry wrote:

Veronese68 wrote:

Plastic.

[googles] So they are. Would have thought plastic would have not been up to the job. I did say I was no engineer :oops:

Lots of stuff is plastic now. Materials technology has moved on a huge amount. But working with parts for old cars as I do it's amazing how many people when offered a part in a better material say no and go for the original material even though the part will never be seen.

My materials knowledge is based on the construction industry, and as has been demonstrated, of limited application to the motor industry.

Aaah now materials technology in the building industry does contain black magic. Push fit plumbing and plastic pipes. I know it works, I know it's been used on the continent for longer than we have. But surely theres magic in there.

Eh? You do know they're just O-rings and a clamp to hold the pipe in the connector?

Now a glass floor you can park a car on is where it gets interesting.

veronese68

rjsterry wrote:

Veronese68 wrote:

rjsterry wrote:

Veronese68 wrote:

rjsterry wrote:

Veronese68 wrote:

Plastic.

[googles] So they are. Would have thought plastic would have not been up to the job. I did say I was no engineer :oops:

Lots of stuff is plastic now. Materials technology has moved on a huge amount. But working with parts for old cars as I do it's amazing how many people when offered a part in a better material say no and go for the original material even though the part will never be seen.

My materials knowledge is based on the construction industry, and as has been demonstrated, of limited application to the motor industry.

Aaah now materials technology in the building industry does contain black magic. Push fit plumbing and plastic pipes. I know it works, I know it's been used on the continent for longer than we have. But surely theres magic in there.

Eh? You do know they're just O-rings and a clamp to hold the pipe in the connector?

Now a glass floor you can park a car on is where it gets interesting.

Ooooh, I like that picture. When I did the kitchen and bathroom at ours I used copper pipe and compression fittings (not confident of my soldering). By the time I put a shower room upstairs, a few years later, I'd accepted push fit. Wow, what a revelation. It's brilliant and I wish I'd used it earlier.

NGale

The Beginner wrote:

NGale wrote:

Most cars these days have Vee belts, hence why the old stocking trick won't work as they are essentially a flat belt.

All cars have V-belts (well 99.9%) modern cars have poly-Vee where a stocking won't work, but they work fine on older (single) Vee belt pulleys.....more study needed?

Simon

I will admit my plant and process principle knowledge is a little rusty these days (I'm more into Naval Architecture). but I do know a stocking wouldn't work on my fan belt as it is one of these fancy 'multiple' vee type belts. I did try, it didn't work.

However the stocking trick did work as a belt on an old Lister engine on the viking powerboat we are rebuilding

rhext

rjsterry wrote:

Veronese68 wrote:

rjsterry wrote:

Veronese68 wrote:

Plastic.

[googles] So they are. Would have thought plastic would have not been up to the job. I did say I was no engineer :oops:

Lots of stuff is plastic now. Materials technology has moved on a huge amount. But working with parts for old cars as I do it's amazing how many people when offered a part in a better material say no and go for the original material even though the part will never be seen.

My materials knowledge is based on the construction industry, and as has been demonstrated, of limited application to the motor industry.

...so, to paraphrase, you can't build a car out of bricks!

veronese68

rhext wrote:

...so, to paraphrase, you can't build a car out of bricks!

Of course you can...

lost_in_thought

NGale wrote:

lost_in_thought wrote:

Well, the question is more was he just a chancer, or did he genuinely think that was the problem? Also, assuming it's option 1, how d'you know he was doing it because you're a woman? Maybe he's just a crook?

And if the larger pulley is out of alignment surely it could still be that?

I think he was being a chancer, he saw a young female and thought he could get a few hundred quid out of her.

I believe alignment would cause other issues from experience with an old car of mine which was always in the garage with varying mechanical problems

As much your prejudice as his?

And one of my VW beetles' belt was forever slipping, alas it was the pulley on the block that was crooked.

merkin

As a tradesman myself who has never ever tried it on, I do find it irritating when people (mostly suspicious women who have watched one too many rogue traders type programs) assume I am trying to pull the wool over their eyes and treat everything I say with distrust.
Does this mechanic have any motive to try and do unescesary work if he works for a main dealer? Do they get commission?

Drysuitdiver

merkin wrote:

As a tradesman myself who has never ever tried it on, I do find it irritating when people (mostly suspicious women who have watched one too many rogue traders type programs) assume I am trying to pull the wool over their eyes and treat everything I say with distrust.
Does this mechanic have any motive to try and do unescesary work if he works for a main dealer? Do they get commission?

most jobs have minutes allocated to them . some jobs are an easy win to hit your minimum minutes some are a pig and you lose out.

the towing electrics on one of my cars is timed at an hour to fit. the technician took 6 , a friend who is a master technician for that advised me it would be a lot longer than the hour and to drop the car off!
a pulley may be timed at 4 hours but can be done in 30 minutes so an easy win on the time front.
servicing of several cars can be done at once if you start dropping the oil on them by the time the last car has been started to be drained the 1st one is drained then you can work along them . thats why dealers don't mind you dropping cars off the evening before, they have the cars there ready to start multiple units at once.

when you go over the minimum minutes you earn bonus.

gtvlusso

NGale wrote:

<rant>
I had the misfortune of having to take my car into the mechanics (a the local dealership as they were the only ones who could book in straight away) because I've been having a few issues with the fan belt slipping. A simple issue of a new fan belt needing fitting.

When did 'How to be patronising to women 101' become a compulsory module in the car mechanics course!!??

The mechanic tried it on by saying the fan belt was slipping because of the larger of the two pulleys and that it would need replacing, so instead of costing no more than £30 it would cost in excess of £200!!

Now Jake checked the car before hand, diagnosed the problem but wasn't able to rectify it himself due to lack of time.

I might only be a student engineer, but in the course of my studies I have learned many things, first and most importantly that you cannot argue with the laws of physics. It seems this mechanic hasn't picked up on that fact!

<rant over>

What did he say was wrong with the large pulley? Bearing problem? Did you get an explanation?

Bear this in mind, on my Mercedes:

Engine: Chain driven - chain only needs replacement/tensioning when it rattles The chain also runs the high pressure fuel pump, oil pump, gearbox oil pump. If a chain is replaced - all of these bearings get replaced and the cogs are checked for replacement.

Poly Belt drives: Water pump, Air con pump, Alternator, Steering pump.

The poly belt needs replacing every 40k miles - the recommendation is also to replace the water pump bearing and pulley (bearing and pully come as a pack): Why? You may ask?

Beacuse the water pump is a bugger to get to and the tension of a new belt exposes the old bearing to quite a bit of force until the belt is worn a bit - staves of potential water pump failure which can be much more expensive in the long run.

So, I would ask yourself, is this guy actually preventing a more long term issue that could cost you time, money + a tow?